Is there a test for this?

 

Open hood, start car(in neutral hehe), rev motor past 4,000 approx, observe if vaccuum lever moves or not.

 

it doesn't move.......

 

Do you have a (92-94 SE) VE-5 spd.?

 

think u gotta have some load on the engine to make the VI to work.

 

if you have an intake, you can hear it open up, as the engine will sound different when the valve opens.


as for testing it, as jeff said.. rev the engine above 4k and see if it opens.

we played with it on the dyno when we were testing my car.. there's about a 10hp jump when it opens, so you should be able to notice if it's there. just by driving.

 

matt: 10hp!?!?!? that's incredible. so on the dyno you just revved past 4k and the lever moved?

i'm losing a lot of power then b/c i don't think mine is working. i'm trying to test to see which parts i need to buy to repair this. is the vacuum applied to the lever below or above 4k? also, does lever open up or close the "runners" above 4k? i thought that the VI closes for the high end power. thanks for the help. i hope i just need to replace the solenoid (anybody know the specs on it so i can test it?)

 

those 10hp give an awesome kick in the pants...my honda friends say "wow, so nissan copied honda and put in vtec?"
Jae

 

anybody with a FSM that can help me out?

 

According to my FSM, you need to apply a vaccuum to the power valve actuator. THe valve should open between -100 and -200mmHG. If it doesn't, replace it. To test the power valve control solenoid valve, apply 12V across the two terminals and make sure there is "continuity" between the two vaccuum lines on it (the picture would really help here). With no current supplied, there should not be continuity. If not, then replace the control solenoid valve. I'm sorry my scanner isn't connected, otherwise I'd scan this page ( EF&EC-329 in my 1994 FSM for anyone that DOES have a scanner).

 

I just checked mine. With the car idling and with the hood open, I just blipped the throttle lever and I can see the actuator arm move. So I believe it's just rpm activated. If yours doesn't work this way(ie.. open at 3,000 or so). I would check the following then dig into Mizere's fsm stuff.

1) Check the vacuum lines to the actuator. Make sure there isn't a hole in the line bleeding off vacuum before it gets to the actuator
2) Check the actuator itself for function. If you don't have a vacuum pump, you could probably just undo one end of the vacuum line to the actuator and suck on it. If the lever moves(or if your car gets really happy), it's probably ok.
3) If these check okay, it's probably the baro switch mentioned in the previous post

 

the baro switch is the green solenoid thing under the throttle body right?

 

Yeah, there are two, one brown and one green. I believe they operate exactly the same but one is for an emissions or idle and the green one if for the VI actuator

 

one more question.... when you rev above 4k, does the vacuum lever move toward the rear of the car or the front. i'm trying to figure out how the VI works w/o having to take my manifold apart. i want to bypass the solenoid (green thing) b/c i want the higher end more than the low end power while i wait on fixing it.

does something open up or close over 4k? i'm guessing that above 4k a butterfly-like part closes up "runners" hence shortning the intake path and increasing the higher end. and in the lower rpms it is open to lengthen the intake path...... dunno. just wanted to put that out to let you know what i'm trying to figure out. thanks for all the input so far.

 

Well when the car is off the vi is also off. So if you move the lever, it will be "on". Which way is that? Simple logic. And you don't really want it "on" all the time.

Have you checked everything??

 

i haven't had the chance to check everything. the only thing i've done is bypass the solenoid to see if the actuator works. it does. i'm going to pull the solenoid out next and test it with a 12v source.

leaving it on all the time would probably hurt something. i do feel my car chokeing a bit after 4k and want to tentatively fix it. i can compensate for the low end loss b/c i have a 5-speed. thanks again for your help jeff.

 

i just tested the solenoid (square green thing) by applying a 12 volt source to it. it works. the vaccum actuator works too. i then hooked up the connections to the solenoid to a multimeter to see if there is any voltage as i revved. no voltage. anybody have any suggestions???? could it be the ecu or just a bad wire connection? is this a commmon problem? thanks.

 

after a week of testing my VI / power valve control, it is finally fixed. i can now fully enjoy the power of a VE 5-speed. thanks for all the help.

 

Good job

what was the problem?

 

The vacuum actuator pulls the rod toward the front, which opens the butterfly. This gives a shorter effective runner length == less suction loss == more high end power. There's a little vacuum storage tank attached to the left shock tower, and a check valve between the tank and the solenoid valve. Make sure those are OK, too. Good luck.

 

i checked all the component first to see if they were working (actuator, solenoid, vacuum hoses). they all checked out to be ok. then i dug a little deeper and checked the wiring from the solenoid to the 12v source and the ECM. it turned out that the wire to the ECM was not continuous. i found where the break was (looking through an *ssload of wires) and bridged it.

my actuator actually starts off at idle with the lever pulled toward the front (makes sense since there should be 12v going across the solenoid hence opening it up to send the vacuum to the actuator). then once i give it a little gas (700-~3500 RPM) it will go towards the back. after ~4k the lever pulls towards the front again. very interesting.